Seed treatment method

ABSTRACT

A method of stimulating root growth of seeds is disclosed in which seeds are treated with an effective amount of an aqueous ammoniacal ionic solution of metal alkanoates. Alkanoates having from 2 to 6 carbon atoms are preferred, with acetates most preferred. Metals selected from the group consisting of boron, calcium, copper, iron, magnesium, manganese, molybdenum, potassium, sodium and zinc are preferred, with zinc particularly preferred. In one embodiment, an aqueous ammoniacal ionic solution of zinc acetate is applied to seeds in-furrow. In another embodiment, seeds are treated with an aqueous ammoniacal ionic solution of zinc acetate prior to planting. In yet another embodiment, an aqueous ammoniacal ionic solution of zinc acetate is mixed with an insecticide and resulting solution applied to seeds in-furrow.

The present application is a continuation of co-pending U.S. patentapplication Ser. No. 08/816,756 filed Mar. 7, 1997 for “SEED TREATMENTMETHOD”, now U.S. Pat. No. 6,386,126, which was a continuation of U.S.patent application Ser. No. 08/289,402, filed Aug. 12, 1994 entitled“SEED TREATMENT METHOD”, now abandoned, both of which are herebyincorporated by reference.

FIELD OF THE INVENTION

This invention relates to a method of applying an aqueous ammoniacalionic solution of metal alkanoates to seeds to stimulate early seedlinggrowth. More particularly, this invention relates to a method ofpretreating seeds with an aqueous ammoniacal ionic solution of metalalkanoates and of applying such solutions to seeds, in-furrow, atplanting.

BACKGROUND OF THE INVENTION

Traditionally, substantially anhydrous liquid ammonia has been injectedbelow the soil surface, under pressure, for use by growing plants as asource of nitrogen. Anhydrous liquid ammonia is typically applied infall—after the end of the growing season, in early spring—prior toplanting, or in late spring—post-emergence, i.e. after a crop hasgerminated and leafed out. While anhydrous liquid ammonia is readilyassimilated by plants and thus is a preferred fertilizer, thepressurized injection methods conventionally used are not suitable foruse under wet soil conditions. When weather conditions are unsuitable,growers may skip scheduled early spring, late spring or fallapplications of anhydrous liquid ammonia. When this occurs, crop yieldsare likely to be reduced unless alternate forms of nitrogen applicationare used.

Plant activants and other fertilizers and materials are sometimescombined with anhydrous ammonia to form augmented solutions forapplication to the soil with the anhydrous ammonia to further enhanceplant growth and increase crop yields. U.S. Pat. No. 3,909,229 for“Plant Nutrients” to Ott, incorporated herein by reference, teachesaqueous ammoniacal ionic solutions of zinc carboxylates, for examplezinc acetate in combination with ammonia, as effective fertilizers. U.S.Pat. No. 3,997,319 for “Fertilizing Method” to Ott, incorporated hereinby reference, teaches the application to soil below the surface of thesoil, a substantially anhydrous liquid ammonia containing an ionicsolution of a zinc carboxylate. This method supplies both zinc andnitrogen to plants growing in the soil. Zinc acetate is disclosed inthis patent as a suitable zinc carboxylate. U.S. Pat. No. 4,352,688 for“Nitrogen Fertilizers” to Ott, also incorporated herein by reference,teaches that low molecular weight alkanoic acids and alkanoate anions,particularly acetic acid and acetate ions, effectively promote plantgrowth and yield by enhancing the ability of nitrogen fertilizers.

As disclosed in the above-identified patents, alkanoic acids andalkanoate anions, for example metal ammonium alkanoates and zincammonium acetate, are applied in conjunction with anhydrous ammonia,often by injection under pressure. When employing this applicationtechnique, application of the alkanoic acid and/or alkanoate aniondepends upon successful application of the anhydrous ammonia. If weatherconditions are unsuitable for application of the anhydrous ammonia,crops growing in or to be planted in the soil to which the anhydrousammonia was to be applied may forego both needed nitrogen and plantgrowth stimulation afforded by the alkanoic acid or alkanoate.

When a scheduled application of an anhydrous ammonia/alkanoic acid oralkanoate combination is missed, a dried or liquid fertilizer containingthe alkanoic acid or alkanoate is sometimes applied as a pre-emergenceor side dressing. However, the effectiveness of side dressing techniqueson growing plants is typically not as great as when a fertilizer isapplied closer to the plant roots.

One agricultural crop additive of the class of aqueous ammoniacal ionicsolutions of metal alkanoates described above is commercially availableunder the ACA® Concentrate 15-0-0 trademark from Platte Chemical Companyof Fremont, Nebr. ACA® Concentrate 15-0-0 is an aqueous ammoniacal ionicsolution of zinc acetate. ACA® us currently available as a liquidcontaining approximately 15% by weight ammoniacal nitrogen andapproximately 17% by weight zinc (hereinafter “ACA®”). ACA® is typicallyapplied at a rate of from ⅓ to ⅔ pint per acre, preferably ½ pint to ⅔pint per acre. Application of alkanoates at these low rates is generallyunderstood to require application of the alkanoate in conjunction with aliquid carrier, such as anhydrous ammonia or a nitrogen fertilizersolution. This requirement derives from the relatively high viscosity ofaqueous ionic solutions of metal alkanoates such as ACA® and theinability of planting equipment to deliver such fluids at the desiredlower flow rates.

Because of the concentrated character of many nitrogen fertilizers,including pressured anhydrous ammonia, care is taken to avoid applyingthese fertilizers directly to the roots of growing plants or in contactwith newly planted seeds. Instead, these fertilizers are conventionallyapplied a distance from the plant roots. For example, ACA®, when mixedwith liquid or dry granular fertilizer and applied as a startersimultaneously with the planting of corn seeds, is typically applied 2″or more to the side of a furrow in which the seeds are placed and 2″ ormore below the level of the seeds in the furrow. By distancing thefertilizer/alkanoate mixture from the corn seeds, the seeds are notburned by the fertilizer and the sprouted plants eventually can accessto the fertilizer/alkanoate mixture after the plants are established.

Thus, application of ACA® and other aqueous ammoniacal ionic solutionsof metal alkanoates near plant roots has traditionally been limited byrestrictions on placement of the carrier ammonia or other fertilizerliquids or solids. Despite this, and although the precise mechanism bywhich the aqueous ammoniacal ionic solution of metal alkanoates enhanceplant growth is not completely understood, it appears that applicationof such solutions is especially important at early leafing stages ofdevelopment of crops such as corn, soy beans and wheat.

It is against this background that the significant improvements andadvancements of the present invention have taken place.

OBJECTS OF THE INVENTION

It is the principal object of the present invention to apply an aqueousammoniacal ionic solution of metal alkanoates to seeds to stimulateseedling and later plant growth and to increase crop yields, withoutinjury to seeds or plants.

It is a further object of the present invention to accomplish theaforementioned object without requiring the aqueous ammoniacal ionicsolution of metal alkanoates be applied to the soil in a carrier mediumsuch as anhydrous ammonia, liquid fertilizer, dry granular fertilizer orother medium.

It is a yet further object of the present invention to accomplish theaforementioned objects as early as possible in the development cycle ofplants without risk of omitting an application of the aqueous ammoniacalionic solution of metal alkanoates because of inclement weather.

SUMMARY OF THE INVENTION

In accordance with the major aspects of the present invention, aneffective amount of an aqueous ionic ammoniacal ionic solution of metalalkanoates is applied directly to uncovered seeds, in-furrow, atplanting. Following placement of the seeds in a furrow, typically in anautomated fashion by a seed planting machine, the solution isautomatically and continuously dispensed onto the uncovered seedsin-furrow and to the surface of the soil of the furrow, directlyadjacent the seeds.

In an alternate embodiment of the present invention, seeds are treatedbefore planting with an effective amount of an aqueous ammoniacal ionicsolution of metal alkanoates.

Preferred alkanoates applied pursuant to the method of the presentinvention contain from two to six carbon atoms, with acetate ions mostpreferred. Preferred metal alkanoates contain agriculturally acceptablemetals selected from the group consisting of boron, calcium, copper,iron, magnesium, manganese, molybdenum, potassium, sodium and zinc, withzinc particularly preferred. The most preferred solution with which thepresent invention may be practiced is an aqueous ammoniacal ionicsolution of zinc acetate.

When applying an aqueous ammoniacal ionic solution of zinc acetatein-furrow to corn kernels in accordance with the present invention, thecorn kernels are preferably placed in-furrow in 15″ to 40″ rows and thesolution is preferably dispensed in-furrow at a rate of ⅓ pint to ½ pintper acre. When applying an aqueous ammoniacal ionic solution of zincacetate in-furrow to soy bean seeds, the soy beans are placed in-furrowin 7″ to 40″ rows and the solution is dispensed in-furrow at a rate of ⅓pint to ½ pint per acre. When applying an aqueous ammoniacal ionicsolution of zinc acetate in-furrow to wheat seeds in accordance with thepresent invention, the wheat seeds are preferably placed in-furrow in 7″to 10″ rows and the solution is preferably dispersed in-furrow at a rateof ⅓ pint to ½ pint per acre.

Employing the aforementioned methods results in stimulation of rootgrowth to seedlings and post-emergent plants at the earliestdevelopmental stages, increased plant growth in later stages, andincreased crop yield, all without apparent injury to seeds or plants.The aforementioned methods have been employed under windy or wet weatherconditions during which application of fertilizer by traditionalpressure broadcast spray methods would typically be avoided.

A more complete appreciation of the present invention and its scope canbe obtained from understanding the accompanying drawings, which arebriefly summarized below, the following detailed description ofpresently preferred embodiments of the invention, and the appendedclaims.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph on which data is plotted illustrating the radicallength in millimeters of germinated corn kernels treated with an aqueousammoniacal ionic solution of metal alkanoates.

FIG. 2 is a graph on which data is plotted illustrating the number oflateral roots present on germinated corn kernels treated with an aqueousammoniacal ionic solution of metal alkanoates.

FIG. 3 is a graph on which data is plotted illustrating the shoot lengthin millimeters of germinated corn kernels treated with an aqueousammoniacal ionic solution of metal alkanoates.

FIG. 4 is a graph on which data is plotted illustrating the seminal rootlength in millimeters of germinated corn kernels treated with an aqueousammoniacal ionic solution of metal alkanoates.

FIG. 5 is a graph on which data is plotted illustrating the number ofseminal roots present on germinated corn kernels treated with an aqueousammoniacal ionic solution of metal alkanoates.

FIG. 6 is a perspective view of a corn planting machine on which ismounted an in-furrow pumping assembly with which the present inventionmay be practiced.

FIG. 7 is a schematic section view of the corn planting machine shown inFIG. 6 showing application of a solution to a seed in a furrow with thein-furrow pumping assembly shown in FIG. 6, taken substantially alongthe line 7—7 of FIG. 6.

FIG. 8 is a schematic section view of the corn planting machine shown inFIGS. 6 and 7, taken substantially along the line 8—8 of FIG. 7.

FIG. 9 is a partially exploded view of components of the in-furrowpumping assembly shown in FIG. 6.

FIG. 10 is an exploded view of a drop tube assembly which is a componentof the in-furrow pumping assembly shown in FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present application, it has been discovered thataqueous ammoniacal ionic solutions of metal alkanoates can besuccessfully applied to seeds to stimulate root and plant growth,without burning or other injury to the seeds. In accordance with thisdiscovery, a method of treating seeds with an aqueous ammoniacal ionicsolution of metal alkanoates has been developed which results inincreased root and plant growth. In addition, a method has beendeveloped by which such solutions can be successfully applied to seedsin-furrow at seed planting at low delivery rates, without need forlarger amounts of a carrier solution or material.

More particularly, it has been discovered that an aqueous ammoniacalionic solution of zinc acetate can be applied directly to uncoveredseeds in-furrow, and to the soil directly adjacent the seeds (that is tosay, within ½″ to the side of the center of the furrow) at planting, atrates of from ⅓ pint to ⅔ pint per acre, with beneficial effect to seedgrowth, early root growth, and subsequent plant development.

The method of the present invention preferably employs an aqueousammoniacal ionic solution of metal alkanoates in which the alkanoatecontains from two to six carbon atoms, with acetate ion most preferred.The metal of the aqueous ammoniacal ionic solution of metal alkanoatesis an agriculturally acceptable metal selected from the group consistingof boron, calcium, copper, iron, magnesium, manganese, molybdenum,potassium, sodium and zinc, with zinc most preferred.

When applying an aqueous ammoniacal ionic solution of zinc acetatein-furrow to corn kernels in accordance with the present invention, thecorn kernels are preferably placed in-furrow in 15″ to 40″ rows and thesolution is preferably dispensed in-furrow at a rate of ⅓ pint to ½ pintper acre. When applying the solution in-furrow to soy bean seeds, thesoy beans are placed in-furrow in 7″ to 40″ rows and the solution isdispensed in-furrow directly to the uncovered seeds and to the soildirectly adjacent the seeds (at a distance of no more than ½″ to theside of the center of the furrow) at a rate of ⅓ pint to ½ pint peracre. When applying an aqueous ammoniacal ionic solution of zinc acetatein-furrow to wheat seeds in accordance with the present invention, thewheat seeds are preferably placed in-furrow in 7″ to 10″ rows and thesolution is preferably dispersed in-furrow at a rate of ⅓ pint to ½ pintper acre.

Application of aqueous ammoniacal ionic solutions of zinc acetatepreferably contain zinc in a range of from 5% to 20% by weight, with aconcentration of approximately 17% by weight zinc most preferred. Anaqueous ammoniacal ionic solution of zinc acetate having a preferredzinc concentration can be produced according to Example I below.

EXAMPLE I

A stock solution of ammonium acetate in aqueous ammonia was prepared bymixing 33.6 parts of glacial acetic acid with 48 parts of water followedby slow addition to the cooled mixture of 18.4 parts of commercialanhydrous liquid ammonia, while maintaining the temperature between 25°and 50° C. After cooling the solution to 10° C., 21.8 parts of zincoxide were slowly added with stirring while maintaining the temperaturebelow 25° C. The zinc oxide dissolved rapidly to afford a stock solutioncontaining 17.5% weight percent zinc which had a pH of 11.4 and aspecific gravity of 1.27.

Prior to the invention of the seed treatment method described herein,the phytotoxicity to seeds and the possible beneficial effects to seedgrowth of aqueous ammoniacal ionic solutions of metal alkanoates applieddirectly to seeds was unknown.

EXAMPLE II

To determine whether application of such solutions to seeds would causeundesirable phytotoxicity and to make a preliminary determination ofconcentrations which would optimally stimulate seed growth, batches of50 field corn seeds were placed in petri dishes containing graduatedconcentrations of an aqueous ammoniacal ionic solution of zinc acetateprepared according to Example I above. The dishes containedconcentrations of the solution of Example I to water of 0 g/l, 0.006g/l, 0.03 g/l, 0.06 g/l, 0.3 g/l, 0.6 g/l, 3 g/l, 6 g/l, 30 g/l and 60g/l. The seeds and solutions were maintained in the dishes for 48 hours.

After soaking in the petri dish solutions, each batch of 50 corn seedswas divided into smaller groups of seeds which were then placed on wetgermination paper. Of each 50 seed batch, 25 of the seeds were placed ongermination paper saturated with water and 25 of the seeds were placedon germination paper saturated with a solution containing 0.6 g of theaqueous ammoniacal ionic solution of zinc acetate of Example I per literof water. Each saturated germination paper/seed set was placed in aseparate plastic bag and sealed. The sealed bags were maintained in thedark in a large container at 80° F. for six days. At the end of sixdays, incubation was deemed complete Radicle length, lateral rootnumber, shoot length, seminal root number and seminal root length ofeach seed were measured. Data obtained for seeds incubated ongermination paper saturated with the dilute aqueous ammoniacal ionicsolution of zinc acetate solution is shown in Table I.

TABLE I Zinc Ammonia Seminal Acetate Radical Lateral Shoot Root Seminal(Example I) Length Root Length Length Root in water (mm) (number) (mm)(mm) (number) 60 g/l 0.0 0.0 0.0 0.0 0.0 30 g/l 0.0 0.0 0.0 0.0 0.0  6g/l 131.9 121.4 78.7 410.0 2.7  3 g/l 232.6 155.5 143.1 371.7 2.5  0.6g/l 240.1 181.1 133.6 405.1 2.3  0.3 g/l 185.9 173.5 105.8 422.2 3.1 0.06 g/l 157.6 77.6 112.5 108.9 1.6  0.03 g/l 75.7 56.4 80.4 107.7 1.7 0.006 g/l 42.0 28.7 62.5 51.7 0.7  0 g/l 70.5 52.8 72.3 62.1 1.0

The data summarized in Table I indicates that phytotoxicity of theaqueous ammoniacal ionic solution of zinc acetate of Example I is notfatal for solution concentrations of from 30 mg/l to 6 g/l water.Phytotoxicity appears fatal for seeds treated with concentrations of 30g/l and above. Most significantly, a substantial and unexpected benefitwas obtained from application of the aqueous ammoniacal ionic solutionof zinc acetate to seeds in concentrations of from 0.06 g/l to 3 g/lzinc acetate solution of Example I to water. Within this concentrationrange, measured growth parameters generally increased with an increasein concentration of the aqueous ammoniacal ionic solution of zincacetate. Above and below this concentration range, almost all measuredgrowth parameters decreased. These tests evidence the significant effectof aqueous ammoniacal ionic solutions of metal alkanoates on theearliest seed growth.

Data obtained from the procedures described in Example I for seedsincubated on germination paper saturated with water only is shown inTable II.

TABLE II Zinc Ammonia Seminal Acetate Radical Lateral Shoot Root Seminal(Example I) Length Root Length Length Root in water (mm) (number) (mm)(mm) (number) 60 g/l 0.0 0.0 0.0 0.0 0.0 30 g/l 0.0 0.0 0.0 0.0 0.0  6g/l 103.9 74.6 63.5 202.8 1.8  3 g/l 214.2 184.0 123.3 381.3 2.2  0.6g/l 205.4 186.8 128.5 684.9 4.3  0.3 g/l 189.9 142.5 122.6 323.7 2.8 0.06 g/l 164.6 102.4 114.5 167.0 1.8  0.03 g/l 99.2 70.5 92.0 124.6 1.6 0.006 g/l 52.9 46.8 69.2 54.6 0.7  0 g/l 83.3 64.7 84.2 95.8 1.6

The data summarized in Table II also indicates that phytotoxicity ofaqueous ammoniacal ionic solutions is not fatal for solutions havingconcentrations of from 30 mg/l to 6 g/l of the aqueous ammoniacal ionicsolution of zinc acetate of Example I to water. Phytotoxicity appearsfatal for seeds treated with concentrations of 30 g/l and above, despitesubsequent germination on water saturated paper. In a pattern similar tothe results obtained with treated seeds germinated on paper saturatedwith dilute aqueous ammoniacal ionic solutions of zinc acetate, earlyseed growth clearly benefited from application of the aqueous ammoniacalionic solutions of zinc acetate in concentrations of from 0.06 g/l to 3g/l to water. Within this concentration range, most measured growthparameters increased with an increase in concentration. Above and belowthis concentration range, almost all measured growth parametersdecreased. The exceptional results obtained in all measured parameterswith seeds treated with 0.6 g aqueous ammoniacal ionic solution of zincacetate per liter of water indicates that this concentration may beindicative of an optimum treatment range.

The graph shown in FIG. 1 compares radical lengths of seeds treated withvarious concentrations of the aqueous ammoniacal ionic solution of zincacetate and germinated on paper saturated with a dilute solution of theaqueous ammoniacal ionic solution of zinc acetate (data from Table I)with treated seeds germinated on water saturated paper (data from TableII). The vertical axis 10 represents radical length, in millimeters. Thehorizontal axis 11 represents the various concentrations of the aqueousammoniacal ionic solution of zinc acetate prepared according to ExampleI with which the seeds were treated. Solid vertical bars 12 representthe radical length of treated seeds germinated in the dilute aqueousammoniacal ionic solution of zinc acetate (Table I). Hollow verticalbars 14 represent the radical length of treated seeds germinated inwater (Table II). As can be seen in FIG. 1, maximum radical length iseffected with seeds treated with from 0.06 to 3.0 g/l of the aqueousammoniacal ionic solution of zinc acetate of Example I to water, whetherthe treated seeds are germinated in a dilute aqueous ammoniacal ionicsolution of zinc acetate or in water.

The graph shown in FIG. 2 compares numbers of lateral roots formed onseeds treated with various concentrations of the aqueous ammoniacalionic solutions of zinc acetate and germinated on paper saturated with adilute aqueous ammoniacal ionic solution of zinc acetate (data fromTable I) with seeds treated and then germinated on water saturated paper(data from Table II). The vertical axis 20 represents numbers of lateralroots formed. The horizontal axis 21 represents the variousconcentrations of the aqueous ammoniacal ionic solutions of zinc acetatesolution prepared according to Example I with which the seeds weretreated. Solid vertical bars 22 represent the number of lateral rootsformed on treated seeds germinated in a dilute aqueous ammoniacal ionicsolution of zinc acetate (Table I). Hollow vertical bars 24 representthe number of lateral roots formed on treated seeds germinated in water(Table II). As can be seen in FIG. 2, maximum number of lateral rootsformed occurs with seeds treated with from 0.3 to 3.0 g/l of the aqueousammoniacal ionic solution of zinc acetate of Example I to water, whetherthe treated seeds are germinated in a dilute aqueous ammoniacal ionicsolution of zinc acetate or in water.

The graph shown in FIG. 3 compares shoot lengths of seeds treated withvarious concentrations of the solution of Example I and germinated onpaper saturated with a dilute zinc acetate solution of Example I (datafrom Table I) with seeds treated and then germinated on water saturatedpaper (data from Table II). The vertical axis 30 represents shootlength, in millimeters. The horizontal axis 31 represents the variousconcentrations of the Example I solution with which the seeds weretreated. Solid vertical bars 32 represent the shoot length of treatedseeds germinated in the dilute zinc ammonium acetate solution (Table I).Hollow vertical bars 34 represent the shoot length of treated seedsgerminated in water (Table II). As can be seen in FIG. 3, maximum shootlength is effected with seeds treated with from 0.06 to 3.0 g/l of theaqueous ammoniacal ionic solution of zinc acetate of Example I to water,whether the treated seeds are germinated in a dilute aqueous ammoniacalionic solution of zinc acetate or in water.

The graph shown in FIG. 4 compares seminal root lengths of seeds treatedwith various concentrations of the solution of Example I and germinatedon paper saturated with a dilute aqueous ammoniacal ionic solution ofzinc acetate (data from Table I) with seeds treated and then germinatedon water saturated paper (data from Table II). The vertical axis 40represents seminal root length, in millimeters. The horizontal axis 41represents the various concentrations of the solution of Example I withwhich the seeds were treated. Solid vertical bars 42 represent theseminal root length of treated seeds germinated in the dilute zincacetate solution of Example I (Table I). Hollow vertical bars 44represent the shoot length of treated seeds germinated in water (TableII). As can be seen in FIG. 4, maximum seminal shoot length is effectedwith seeds treated with from 0.3 to 3.0 g/l of the aqueous ammoniacalionic solution of zinc acetate of Example I to water, whether thetreated seeds are germinated in a dilute aqueous ammoniacal ionicsolution of zinc acetate or in water. The outstanding results obtainedwith seeds treated with 0.6 g/l of the solution of Example I to water(i.e., mean seminal root length of 684.9 mm per Table II) which weresubsequently germinated in a water saturated environment indicates thatseed growth stimulation resulting from initial seed treatment, asindicated by seminal root length, may benefit from access to pure waterduring germination.

The graph shown in FIG. 5 compares numbers of seminal roots formed onseeds treated with various concentrations of the aqueous ammoniacalionic solution of zinc acetate of Example I and germinated on papersaturated with a dilute aqueous ammoniacal ionic solution of zincacetate (data from Table I) with seeds treated and then germinated onwater saturated paper (data from Table II). The vertical axis 50represents the average number of seminal roots formed. The horizontalaxis 51 represents the various concentrations of the solution of ExampleI to water with which the seeds were treated. Solid vertical bars 52represent the number of seminal roots formed on treated seeds germinatedin the dilute aqueous ammoniacal ionic solution of zinc acetate (TableI). Hollow vertical bars 54 represent the number of seminal roots formedon treated seeds germinated in water (Table II). As can be seen in FIG.5, the maximum number of lateral roots formed on seeds treated with from0.3 to 6.0 g/l of the aqueous ammoniacal ionic solution of zinc acetateof Example I to water, whether the treated seeds are germinated in adilute aqueous ammoniacal ionic solution of zinc acetate or in water. Inaddition, the noteworthy results obtained with seeds treated with 0.6g/l of the solution of Example I to water (i.e., average 4.3 lateralroots formed per Table II) which were subsequently germinated in a watersaturated environment indicates that seed growth stimulation resultingfrom initial seed treatment, as indicated by seminal root number, maybenefit from access to pure water during germination.

EXAMPLE III

Field tests were conducted to determine the effect of aqueous ammoniacalionic solutions of zinc acetate treatment on early plant growth. Cornseeds were placed in petri dishes containing the aqueous ammoniacalionic solution of zinc acetate prepared in accordance with the Example Idiluted in water in the following proportions: 0 g/l, 0.006 g/l, 0.03g/l, 0.06 g/l, 0.3 g/l, 0.6 g/l, 3 g/l, 6 g/l, 30 g/l and 60 g/l. Seedsremained in the solutions in the petri dishes for 24 to 48 hours, afterwhich they were planted in 30 inch rows, 2″ deep and 8″ apart. Viability(as measured in percent of plants successfully emerging) and stemdiameter (in millimeters) were measured. Data obtained is summarized inTable III.

TABLE III Emergence Stem Zinc Ammonia (% of plants Diameter Acetatesprouted) (mm) 60 g/l 0 0 30 g/l 0 0 6 g/l 23 6.5 3 g/l 85 7.7 0.6 g/l95 8.8 0.3 g/l 97 8.7 0.06 g/l 93 8.4 0.03 g/l 93 8.5 0.006 g/l 96 7.8 0g/l 92 7.8

As may be seen in Table III, satisfactory plant emergence and stemgrowth occurred with seeds treated with an aqueous ammoniacal ionicsolution of zinc acetate prepared in accordance with Example I anddiluted in water in from 0 g/l to 3 g/l. Seeds treated with 30 g/l ofthe solution of Example I to water and above succumbed. Plant viabilityof seeds treated with 6 g/l of the solution of Example I to water isuncertain.

To treat seeds in the field with the preferred smaller volumes ofaqueous ammoniacal ionic solutions of metal alkanoates (for example, ⅓pint to ⅔ pint per acre), low fluid delivery rates must be maintained.However, as mentioned previously, application of such solutions at lowdelivery rates is difficult. Foreign particles tend to occlude smalldispensing orifices otherwise required to dispense solutions at such lowrates. Variations in ambient temperature effect the viscosity of suchsolutions, which results in unacceptable variation in fluid deliveryrates.

Despite the fluid delivery problems described above, a method ofapplying aqueous ammoniacal ionic solutions of metal alkanoates to seedsin-furrow has been developed. This method is best understood withreference to the component parts of an in-furrow pumping and dispensingassembly 60 (FIGS. 6 through 10) attached to a planting machine 62 (FIG.6) suitable for planting corn, soy beans, wheat and other seeds.

As is shown in FIGS. 6, 9 and 10, a tank 64 holding an aqueousammoniacal ionic solution of metal alkanoates is mounted to a frame 66attached to the planting machine 62. The tank 64 includes a control vent66 to prevent excessive vapor/air exchange when liquid is present in thetank 64. A pump 68 is also mounted to the frame 66. A screen 69 filtersforeign material from the solution before it enters the pumping system.Tubing 70 connects the tank 64 to the pump 68 and tubing 72 connects thepump 68 to a manifold 74. The manifold 74 is connected to drop tubesubassemblies 75, through which liquid is dispensed to the furrows(FIGS. 7 and 8).

As is best shown in FIG. 10, each drop tube subassembly 75 includes anozzle body 76 and coupler 78 between which is mounted a ball checkvalve screen 77 and an orifice plate 79. Mounted in the coupler 78 is amicrotubing 80 having first and second open ends 81 and 83 and furtherhaving a preferred inside diameter of 0.035″-0.075″. The microtubing 80is mounted in conduit 82 having a preferred diameter of 0.50″. Theconduit 82 is mounted in a stainless steel drop tube 84, which extendsin a downward direction and terminates adjacent to but spacedapproximately 2″ to 4″ above the soil surface (FIG. 7).

During planting, the in-furrow pumping and dispensing assembly 60 isoperated continuously, dispensing liquid at a preferred rate of ½ pintof the aqueous ammoniacal ionic solution of metal alkanoates per acre.Despite foreign particles in the product supply tank, the preferred rateis maintained by the combination of the special in-line check valvescreen 77 and orifice plate 79, which functions as a metering orifice.It has been further discovered that maintenance of the preferred liquiddispensing rate requires the microtubing 80 be kept as straight aspossible, avoiding unnecessary bending.

EXAMPLE IV

Forty-eight 1200′ rows 30″ apart were planted with corn to which ½ pintper acre of the aqueous ammoniacal ionic solution of zinc acetateprepared in accordance with the method of Example I, was applied with tothe uncovered seeds and to the surface of the furrow directly adjacentthe seeds (to a distance of at most ½″ to the side of the center of thefurrow) with an in-furrow pumping and dispensing assembly 60 attached toa planting machine 62 as described above. Thirty-six check rows 1200′long and 30″ apart were planted with corn to which no Example I solutionwas applied. The treated rows yielded 193.5 bushels of corn per acre,while the check rows yielded 185.7 bushels of corn per acre. Thisrepresents an increased yield of 7.8 bushels of corn per acre.

EXAMPLE V

Ninety-six 560′ rows 30″ apart were planted with corn to which ½ pintper acre of the aqueous ammoniacal ionic solution of zinc acetateprepared in accordance with Example I was applied to the uncoveredseeds, in-furrow, and to the surface of the furrow directly adjacent theseeds, to a distance of at most ½″ to the side of the center of furrow,with the in-furrow pumping and dispensing assembly 60 attached to aplanting machine 62 as described above. Ninety-six check rows 560′ longby 30″ apart were planted with corn to which no Example I solution wasapplied. The treated rows yielded 147.2 bushels of corn per acre, whilethe check rows yielded 143.9 bushels of corn per acre. This representsan increased yield of 3.3 bushels of corn per acre.

It is has been further discovered that the aqueous ammoniacal ionicsolution of zinc acetate of Example I may be mixed with an insecticideand applied directly to seeds, in-furrow, using the in-furrow pumpingand dispensing assembly 60 shown in FIGS. 6 through 10. One illustrativeexample of application of such a mixture is described in Example VIbelow.

EXAMPLE VI

A solution prepared in accordance with Example I, was mixed withFuradan, an insecticide available from FMC Corporation, and applieddirectly to uncovered seeds, and to the surface of the furrow directlyadjacent the seeds, to a distance of at most ½″ to the side of thecenter of the furrow, in-furrow to corn at planting at a rate of ⅔ pintof the zinc acetate solution of Example I per acre. The row treated withthe aqueous ammoniacal ionic solution of zinc acetate/insecticidecomposition yielded 120 bushels of corn per acre. Check rows to whichonly the insecticide was applied yielded 93.8 bushels of corn per acre.The yield of rows treated with the aqueous ammoniacal ionic solution ofzinc acetate/insecticide composition represent an increased yield of 28%over the rows treated only with insecticide. This increased yield is notbelieved to be attributable solely to the solitary effects of theaqueous ammoniacal ionic solution of zinc acetate, but rather isbelieved to evidence a synergistic effect between the zinc acetatesolution and the insecticide.

The aforementioned methods have been employed under windy weatherconditions during which application of fertilizer by traditionalbroadcast spray methods would typically be avoided.

Presently preferred embodiments of the present invention and many of itsimprovements have been described with a degree of particularity. Itshould be understood that this description has been made by way ofpreferred examples, and that the invention is defined by the scope ofthe following claims.

What is claimed is:
 1. A method of treating seeds prior to plantingcomprising the step of wetting the seeds directly with a non-phytotoxicamount of an aqueous ammoniacal ionic solution of metal alkanoatescontaining alkanoate ions of from 2 to 6 carbon atoms each.
 2. Themethod of claim 1 wherein the metal of the solution is selected from thegroup consisting of boron, calcium, copper, iron, magnesium, manganese,molybdenum, potassium, sodium and zinc.
 3. The method of claim 1 whereinthe solution is an aqueous ammoniacal ionic solution of zinc acetate. 4.The method of claim 3 wherein the solution contains from 5% to 10% byweight zinc.
 5. The method of claim 3 wherein the solution contains from5% to 20% by weight zinc.
 6. The method of claim 3 wherein the solutioncontains approximately 15% by weight zinc.
 7. A method of preparing aseed treatment composition and treating seeds with the composition priorto planting, comprising the steps of: preparing an aqueous ammoniacalionic solution of zinc acetate containing from 5% to 20% by weight zinc;and treating the seeds directly with the aqueous ammoniacal ionicsolution of zinc acetate.
 8. The method of claim 7 wherein the seeds arecorn kernels.
 9. A method of accelerating root growth in seedlingscomprising the step of treating seeds directly prior to planting andgermination with a non-phytoxic amount of an aqueous ammoniacal ionicsolution of zinc acetate containing from 5% to 20% by weight zinc.